1. Field of the Invention
The present invention relates to conveyor systems, and more particularly, is directed to the crawler chain drive of a self-propelled articulated conveyor system adapted to be driven along the mine surface by an elongated crawler chain and which conveyor system is capable of traversing curvilinear paths.
2. Description of the Prior Art
In mining operations, especially underground mining operations, such as, coal mining or the like, conveyors or series of conveyors are used to transport the mined ore from the mine. Normally, there is a main conveyor that moves the mined material along a fixed path. The main conveyor has a terminal end at a fixed location for receiving the material being mined. In the past, shuttle cars or other short distance haulage vehicles have been used to transport the mined material from the mining machine to the fixed terminal end of the main conveyor. The use of shuttle cars and other such haulage vehicles is intermittent, time consuming, and inefficient in not providing for the continuous transport of the mined materials from the mining machine to the fixed conveyor. Thus, in more recent years there have been several developments directed toward a mobile articulated conveyor that provides for continuous transport of the discharge of a continuous miner to the main conveyor as the miner advances into the mine face and changes the direction of its forward movement. Such mobile articulated conveyors are particularly adaptable to "room and pillar" type coal mining operations wherein the mobile conveyor follows the continuous miner and changes in direction as the machine penetrates into the mine face in ne room and then is backed out and set to work in the mine face of another room while roof bolts are installed in the recently mined room. The mining machine is then backed out of this second room and set to work in either the recently roof-bolted room or it may go on to still another room.
One of these more recently developed mobile articulated conveyors is shown in the Payne et al patent, U.S. Pat. No. 3,707,218, and sold under the trade designation "Serpentix". The Serpentix conveyor has an endless trough shaped, accordion-pleated belt supported on a vertebrae-like member which, in turn, is supported on the mine floor by stanchions. The stanchion supported conveyor was cumbersome and did not lend itself to frequent shifting of the conveyor path from room to room. Thus, Craggs, as shown in U.S. Pat. No. 3,920,115, suspended the Serpentix conveyor from an overhead monorail and thereby provided a flexible frame conveyor which could be attached to the surge car behind a mining machine. The conveyor could now follow the mining machine as it moved from one room to another in performing its mining operation.
Another development of such mobile articulated conveyors is disclosed in McGinnis U.S. Pat. No. 3,701,411 which shows a conveyor comprised of an endless belt supported on a train of pivotally interconnected portable cars or carriages. Each of the carriages are supported on ground engaging wheels thereby providing mobility to the conveyor. A self-propelled tractor is connected to the conveyor train to move it from one location to another. Another development along the same lines can be found in U.S. Pat. No. 3,863,752.
A later McGinnis patent, U.S. Pat. No. 4,061,223, discloses a mobile articulated conveyor suspended from an overhead monorail. Shown is a U-shaped conveyor belt carried by a plurality of individual carriage units suspended from the overhead monorail. The carriage units are fastened to one another by a resilient, flexible spline member which provides for positioning of the carriage units around vertical and horizontal curves. The conveyor belt is driven by a separate power belt and guided by guide rollers.
The Assignee of Applicant's invention has obtained U.S. Pat. No. 4,339,031 which discloses a mobile monorail suspended conveyor system. While this conveying system has shown promise in higher seams of coal and other mineral mining, there is a limit to the seam height in which one can utilize a conveyor system suspended from an overhead monorail.
United Kingdom Pat. No. 1,373,170 discloses a self-propelled conveying system which can convey minerals and can move itself from one place to another after the conveying function is no longer required. As can be seen, an obvious draw back to this system is that the conveyor is not capable of continuously conveying material from the input end to the discharge end while the conveying system is being moved to another site.
Co-pending U.S. patent application Ser. No. 832,188 discloses a self-propelled conveying system which includes an endless elastomeric orbitally movable conveyor belt for conveying coal from the input end to the discharge end of the conveyor disclosed. Various discharge methods are shown in applicant's co-pending application, however, these arrangements all require relatively high mine passageways and have been discovered to be unacceptable on most applications.
A crawler chain to be used on a conveyor such as that disclosed in U.K. Pat. No. 1,373,170 is disclosed in U.S. Pat. No. 4,332,317. A troughed conveyor belt drive chain is shown in U.S. Pat. No. 4,282,971.